While no official explanation has surfaced (yet), new footage has emerged from deep inside the mysterious crater on the Yamal Peninsula - known as the 'end of the world' to locals - in Siberia. There are many theories as to what caused the hole, including aliens, a meteorite, a stray missile, or an explosive gas cocktail released due to global warming. Continue reading for a video from Russian scientists who recently returned from the first expedition to look inside the giant hole.

Andrey Plekhanov, senior researcher at the Russian Scientific Centre of Arctic Research, reports: "The crater has more of an oval than a circular shape, it makes it harder to calculate the exact diameter. As of now our estimates is about 98ft (30 metres). If we try to measure diameter together with soil emission, the so-called parapet, then the diameter is up to 197ft (60 metres)."